The present disclosure relates to a cleaning member clearing adhered developer from a detection range of a developer amount detecting part, and to a developing device and an image forming apparatus.
An image forming apparatus forms an image, such as a toner image or the like, on a photosensitive drum by, for example, a developing device developing an electrostatic latent image formed on the photosensitive drum by using a developer such as toner or the like. This image is transferred to a sheet by a transferring unit, and is fixed by a fixing part, and then is ejected out of the image forming apparatus.
The developing device includes, for example, an agitating member agitating the developer contained in a housing, and a developing roller carrying the agitated developer and supplying the developer to the photosensitive drum. Furthermore, the developing device includes a developer amount detecting part detecting whether or not a sufficient amount of the developer is contained. The image forming apparatus performs a control such that the developing device is replenished with the developer if the developer amount detecting part does not detect a sufficient amount of the developer. Due to this, the amount of the developer in the housing is kept constant, so that desired images can be formed in a good manner.
However, when the developer stagnates in the housing and adheres to a detecting surface of the developer amount detecting part and others, even if the amount of the developer is actually insufficient, the developer amount detecting part may falsely detect that the amount of the developer in the housing is sufficient. Therefore, in order to clean the detecting surface of the developer amount detecting part, the developing device is equipped with a cleaning member in some image forming apparatuses.
In an example of such a developing device, the cleaning member has an elastic part that is fixed at a detecting surface side from a rotation shaft of an agitating member and that is elastically deformable in a parallel direction to the detecting surface, and a cleaning part that is connected to the elastic part and that slidingly contacts the detecting surface as the agitating member rotates. Then, the length from an axis of the rotation shaft to a distal end portion of the cleaning part is designed to be longer than the length from the axis of the rotation shaft to an inner wall surface of a casing. This cleaning part includes a first cleaning part constructed of an end of a first coil spring part that extends in a substantially perpendicular direction to the rotation shaft, a second cleaning part formed by bending a distal end of the first cleaning part substantially perpendicularly to the detecting surface of the detecting means and then bending a distal end of the bent part substantially perpendicular in a direction that has a predetermined angle with respect to the first cleaning part, and a third cleaning part formed by substantially perpendicularly bending a distal end of the second cleaning part in a direction toward the detecting surface.
However, the cleaning member provided on the developing device is not able to clear the developer stagnating at a location apart forwardly from the detecting surface of the developer amount detecting part, even if the cleaning member passes over the detecting surface. Even if the cleaning member is merely bent with respect to the detecting surface, the developer stagnating at the location apart forwardly from the detecting surface is not sufficiently cleared, and then, the developer may sometimes remain at that location. Then, in the case where the detection range of the developer amount detecting part reaches a location in front of the detecting surface, the developer amount detecting part detects the developer remaining in front of the detecting surface, and therefore, cannot accurately measure the amount of the developer present in the housing, but falsely detects that the amount of developer is sufficient. That is, there is caused a problem that a desired sensor output cannot be obtained.
If another component part is added to the cleaning member in order to clear the developer resining at a location apart forwardly from the detecting surface of the developer amount detecting part, there is a possibility of increasing the number of man-hours for the production of the cleaning member and the production cost.